Radioactive solutions called radiotracers or radiopharmaceuticals, have found applications in various medical fields, in particular in medical diagnostic and therapeutic fields. In recent years the advance of Positron Emission Tomography (PET), which use radionuclides (radioisotopes) of significant higher radiation energy than more conventional nuclear medicine isotopes, has raised some concerns about hand and body radiation exposure received by the persons preparing the dose.
The dangers of ionising radiation are well known and apply to all persons being exposed to radiation, including the staff involved in the preparation of radioactive solutions. Dose fractionation of the radioactive solutions is usually a manual process, performed behind a lead shielded screen to minimal exposure to radiation. However, the performance of this task is time consuming, as the operator needs to withdraw by successive iterations, small volumes of the radiotracer, until he reaches the targeted dose.
After each withdrawal the needle needs to be re-capped and the syringe placed in a dose calibrator to determine if more or less of the radioactive solution should be processed in or out of the syringe. When the targeted dose has been achieved (within ±10%), the syringe may be topped up with saline to obtain a reasonable volume.
Before being released or dispatched for clinical use, the syringe is placed again in the dose calibrator to print out the accurate dose record. To date, very little attempt has been made by manufacturers to design automated equipment capable of withdrawing a dedicated radioactive dose into a disposable sterile syringe or vial.
The very few systems currently on the market are expensive and bulky and are not widely available. Other more affordable systems are either not technically practical or do not achieve efficient radiation protection and need to be operated in a shielded environment. In addition, most of these apparatus rely on the pre-requisite knowledge of the volumetric radioactivity (Ci/mL or Bq/mL) of the stock solution to determine the corresponding volume and hence the radioactive dose to be dispensed.